Note: Descriptions are shown in the official language in which they were submitted.
HOE 73iF 264
l~S~580 g
Thi~ invention relatQq to a th~rmopla~tic compositlon con-
sisting of a vinyl chloride polymer and ~ chlorinated low pres-
sure polyethylene.
It has been proposed to elastify polyvinyl chloride and
vinyl chloride copolymers by the addition of chlorination pro-
ductY of polyolefins obtained by chlorinating polyolefins in
aqueous suspension and having a chlorine content of from 25 to
50 % by weight (cf. German Patent 1,469,990 and German Patents
1,236,774 and 1,266,969).
To obtain chlorination products having a good elastifying .
effect combined with a sufficient fineness o~ grain ~he chlorin-
ation has to be carried out in the presence of fine-grained
inert, inorganic or organic additives to ~void agglomeration.
As inorganic additives silicic acid or kieselguhr have been
proposed (cf. ~erman Patent 1,420,407).
The relatively 1arge amount of silicic acid, whcih must be
added to the ch~ination reaction as anti-agglomeration agent
and which partially remains in the final blend when the chloro-
polyolefln i~ mixed with polyvinyl chloride, haq a detrimental
ef~ect on the rheological and mechanical p~operties of the
blend.
It has now been ~ound that mixtures o~ ~rinyl chloride poly-
mers and chlorination products o~ polyole~ins can be produced
which d~hot have the a~oresaid disadvanta~es and are well
suitable for dry blend ~echnique by using ~ chlorinated low
pressure polyethylene prepared by chlorina~ing in aqueous hyd*o- ~ :
chloric acid, pre~erably in the presence ~ silicic acid having
a large sur~ace ~nd a si'oxane oil.
2g The present in~ention provides a thermoplastic composition
- ~
. ,; , `: ~ '
; .` , ' ' ' ; . ' ' '' ' ~ -`' ;:'; ' '; ' ., ~ :.
: ' `. . . ''' ,'; ' ` ` '` ''
.:., ...... ., , ''~ ' '-. ,' .
'` ' .'. ' ' ' : '
. HOE 73/F 264
105~
essentially consisting of
a) 98 to 50 % b~ weight of a vinyl chloride polymer and
b) 2 to 50 ~ by weight of a chlorinated low pressure poly-
ethylane. havlng a chlorine content of 25 to 42 % by weight,
a reduced specific viscosity o~ 1 to 5 dl/g, a residue
value of 2 to 40 %, measured by extraction with toluene~ i
acetone in a proportion of 1 : 19 and a swelling value of ,;
10 to 70 ~, measured in methylcyclohexane, and obtained by
chlorinating a low prcssure polyethylene in aqueous hydro-
chloric acid having a strength of from 10 to 35 ~, preferably
15 to 30 ~ in the presence of O to 2 ~ by w0ight of silicic
acid and O to 1.0 % by weight of a siloxane oil, the percentages ~.
being calculated on the low pressure pol~-e~ylene used, at a
chlorination temperature of from 50 to 130C, at least 10 % by
welght of chlorine being incorporated at a tamperature of from
120 to 130C.
,:
The present invention also provides a process for the
manufacture of a thermoplastic composition by mi~ing .
a) 98 to 50 ~ by weight of a vinyl chloride polymer and
b) 2 to 50 ~ by we~ght of a chlorinated low pressurs poly-
, ethylene
ha~ing a chlorine content of from 25 to 42 % by weight, a re-
duced speci~ic viqco~ity of 1 to 5 dl~g, a residue value of from
2 to 40 %, measured by extraction with toluene/acetone in a
proportion of 1 : 1, and a swelling valu~ of ~rom 10 to 70 %,
measured in methylcyclohexane, prepared by chlorinating a pre-
~erably fine-grained low pressure polyeth~lene in aqueous hydro-
chloric acid of`10 to 35 ~, preferabl~ 15 to 30 ~, ~trength in
Z~ the presence of O to ~ % by weight of silioic acid and O to 1.0~ -
~, _ 3 _
`- ' .:. :. ' . - . . .
~ ~ . -- - : . :
- ' : . : ~ :'
~OE 73/F 264
~(~5~5~ilV ~ '
by weight of a i~iloxane oil, the p~rcentag0s being calculated
on the starting polyethylene~ at a chlorinatlon temperature o~
from 50 *o 130C, the low presiqure polyethylene being possibly
thermally treated or prssintered at a temperature in the range
o~ from 100C~-i~ cryAtallite melting point and at least 10 %
of the chlorine being incorporated at a temperature of from 120
to 130C~
The thermoplastic composition consists of 98 to j50 % by
weight pre~erably 95to 80 % by weigh*,of polyvinyl chloride or
a copolymer o~ vinyl chloride with other comonomers, such as
vinyl acetate acrylic acid esters or methacrylic acid esters,
the amount o~ comonomer units in the polymer being at most 20
by weight, preferably 1 to 5 % by weight. The K value o~ the
polymer is expediently in a ranga o~ from 50 to 80.
The remainlng ~ to 50 % by weight, pr~ferably 2 to 20 ~ by ~`
weight o~ the thermoplastic composition of the invention consists
of a chlorinated low pressure polyethylene o~ high molecular
weight containing 25 to 42 % by weight, p~ferably 30 to 40 $
by weight,o~ chlorine. The distribution o~ the chlorine atomes ~;
2n in the polyethylene grains, i.e. the degr~e of "pen~rating or
through chlorination" iq oharacterizèd by the reisidue value
according to the toluene/acetone method and the swelling value ~ ;
in methylcyclohexan~. The chlorinated low ~resqure polyethylene
suitable for making the compositions of the invention shall have
a residue value of 2 to 40 ~, pre~erably 2 to 30 %, and a swel-
llng value of 10 to 70 %, pre~erably 20 to 50 %. ~oreover, it
shall have a reduced specific viscosity o~ 1 to 5 dl/g, pre-
~erably 1 to ~.5 dljg.
29 The chlorinated low pre~ure polyethylene o~ high molecular
.
:: . :` . `~ .:. `. ` --
~: ` - ` ` ' ` . ` , ,, .:
~:" ` ` :'. `, . . `, , , ~
OE 73/F 264
-" ~0515~0.
~eight is fins-grainQd and-can readily b~ mi~ed homogeneously
with the ~inyl chloride polymer powder.
The chlorinated low pressure polyethylene to be used
according to the invention is produced ~y chlorinatin~ ~ne-
grained low pressure polyethylene, ~hich may have been therm-
ally treated or pre-sintered for 5 to 300 minutes at a temper-
ature of from 100 C to its crystallite melting point (cf.German
Offenlegungsschrift 1,720,800), in hydrochloric acid expedi-
`ently 3 to 30 times the amount of acid is used, referred to the
low pressure polyethylene. The chlorination is started at a
temperature of from 50 to 100C and terminated at 120 to 130C.
The chlorination is advantageously started in a temper-
ature range of from 70 to 90C, continued with continual
temperature increase and terminated at ~ t~mperature ranging
from 120 to l30 C, Alternati~ely, the chlorination can be
effected in two steps, i.e, it is started at a temperature of
from 50C to 100 C, the chlorine supply is interrupted while
the temperature is raised to 120 to 130C and the chlorination
i9 then conti~ued and terminated at that temperature.
The low pressure polyethylene used as starting material
ha~ a reduced specific viscosity of 1 to ~ dl/g, preferably 1
to 3.5 dl/g-
By silicic acid present in the chlo~ination as agglomer-
ation inhibitor the ~arious hydrous or anhydroua types of
finely porous silicon dioxide prefarabl~ having a large sur-
face are understood`. Their inner surface should expediently be
in the range of from 50 to 400 CD /g acGording to BET (Brunauer,
Emmet and Teller)~ prefe~abl~ 150 to 300 cm2/g.
29 In goneral the silicic acld ha~ a ~ean partlcle size of
- 5 -
'`, ' ~
~ ' . . :
~ E 73/F 264
1~5:1581~ ' ~
from 1 to 50 ~ . 1. :
By the addition of 9il~ CiC acid an~ ~ilo~ane oil the anti-
ag~lomeration e~ect o~ hydrochloric acid is impro~ed,
Such an addition i~ therefore preferr~d. In gen~ral 0.1 to 2 %,
pre~erably 0.1 to 1 % by weight Or silieic acid in combination
with 0.01 to 1.0, preferably 0.02 to 0.7 % by ~eight,of
.~$10~ane oil, each tima caloulated on th~ low pressure poly-
ethylene used, are su~ficisnt. The a~ount of ~ilicic acid and
~iloxane oil is not strictly limited, in 90me cases higher
amounts may also be used, whereby the agglomeration inhibition
1~ further impro~ed but disa~vantages fo~ the blend with poly-
vinyl chloride must be taken into consideration.
The organo-silicon compounds or sil~ana oils to be used
aocording to the in~ention are liquid pol~iloxanes consicting
f the recurring unit
~~1 - ~ :,
-o-fi_ _ - ~
OR2 x
- in which Rl and R2 each represents an alkyl radical preferably
haYing from ~ to 6 carbon atom~,an aryl rad~c~l,preferably
a phenyl or an aralkyl radical preferably ha~ing from 7 to 12
carbon atom~,and X is an integer of ~ro~ 10 to 1,OOO.The ~i5-
cosity of the siloxane oils at Z~ C issuitably inthe ra~ ~ ~om ro
to 500,000 centistokes, more suitably 500 to 50,000 centi-
Jtokes. There are mentioned, by way of e~a~ple, dimethyl-,
diethyl-, dipropyl-, methyl-ethyl-, dioc~y~-, dihèxyl-, me~hyl-
propyl-, dibutyl- and didodeorl-poly~iloxan.es. ~ompounds o~
.29 the dimethyl-polyYiloxaIl~ series proved to ~e especially ad-
- S - '
,~
:. : . : : . : . . .
, : . . . ~ : - -: ~ .- - - . -
~~ 73/F 264
51~80 ~ ,
vantageous. -
The 9ilicic acid component and the polysiloxane, which are
pos~ibly pre-mixed, are expediently added prlor to or at the
beginning of the chlorination within a temperature interval in
which the melting point o~ the polyethylene is not yet reached.
According to another mode of operation the ~ilicic acid is
first added alone and the siloxane oi7 is then admixed during
the course of chlorination. A pos~ible ~light agglomeration can
be counter-acted at least partially by the later addition of
siloxane oil, even if it is made prior to drying.
It i9 also possible, o~ course, to add the intended amount
of qiloxane oil in portions during ~ome or all process steps.
Tha thermoplastic composition according to the invention
may additionally contain known PVC ~tabilizers, ~or example
barium or cadmium laurate, epoxide stabiliz~r~, organic phos- ;
phiteq, tin or lead compounds, as well as ~ther known additi~es.
for example W absorbers, lubricants, prnoes9ing auxiliaries,
dyes and pigments.
Depending on the proportion o~ chlor~nated low pressure
polyeth~lene, the thermoplastie compo~itiqn o~ the in~-ention e~n
be used for making pipes, profiles, plate~, sheets, cables,
fle~ible tubes~in~ection moulded articles and other shaped
structures. Owing to the uniform ~ineness o~ the grain,~the
composition can be easily prooessed by the dry blend technique.
Mi~ing of the component9 in the plasticize~ ~tate i9 not required.
To characterize the chlorinated low pressure polyethylenes
to be uqed according to the in~ention the following met~ods
were u~ed:
29 1) Residue Yalue accordlng to the tolue~e~acetone (TAC) method:
~ _ 7 _
'.' ' - '-: ' ' ' ' ` ` , ' .,' ~
:'~ " ~' .' ~ . . . - : ' . .. . ..
~ HOE 7~ 264
--` lOSle~
4 grams of the chloropolyeth~ylene to be te~ted were re-
fluxed for 1 hour in 100 ml of a 1 : 1 mixture o~
toluene and acetone. The amount of i~soluble re~idue
consisting of insufficiently chlorinated portions is
a measurement for the through chlorination of the poly-
ethylene particles. The smaller the residue the better the
chlorination product is suitable for the compositions of
the invention. I -
2) Swelling value in methylcyclohexane (MCH)-
The increase in weight of a sample after a 24 hour storage
in methylcyclohexane is a ~urther measurement for the
through chlorination of the polyethylene particles.
Portions which have not been chlorinated to a sufficient
extent ~well very little. Products having a high swelling
value are e~pecially ~uitable.
The ~ollowing examples illustrate the invention.
E X A M P L E 1-
.
The chloropolyethylene used was prep~red as follows:
In a chlorination vessel 100 parts by~ weight of low pressure
polyethylene having a reduced specific vi~c09ity of 1.3 dl/~,
in 900 part~ by weight of 20 ~ hydrochloric acid were chlorin-
ated, first at 80C until a chlorine cont~t of 28 ~ by weight
had been reached and then at 121.5C to a ~inal chlorine
' content of 39.2 % by weight.
The product had a TAC value of 13 ~ and a MCH value of
14 %.
A mixture of 10 part~ b~ waight o~ the abo~e chlorination
product and 90 parts b~ weight of suspen~ion pol~vinyl chloride
29 having a K value o~ 70 was rolled for 10 ~inutes at 175C with
- 8 -
'':` . ' ~ '` ` . `' ' ''.~ ', ' ''' ,':' ' ':
EOE 73/~ 264
S~SE~Q
the addition of 3 part~ by weight Or barium/cadmium stabilizer
and 1 part by weight of diphenyl-Octyl ph~phite. The plates
moulded from the blend had the ~oll~wing ~alues
Notched impact strength acoording t~ DIN 53,453 41.7 cm g/cm2
Impact strength at -20C according to D~N 53,453 "without break"
Notched tensile impact strength (DI~ 53,4~8) 197 cmkg/cm
COMPARATIVE EXAMPLE
The same low pressure polyethylene was chlorinated under
the conditions specified above~ but in wa~er without additio~
of hydrochloric acid. The polymer agglomerated to a large
extent 90 that further ch~rination Wa9 much impeded. A chlorin-
ation product was obtained having a chlorine contentlof 39.1 ~ ~`
by weight, a TAC value of 45 ~ and a MC~ valua of 3 ~. A b1end
of 10 % by weight of the said chlorinati~n prod~ct with 90
by weight of suspension polyvinyl chloride having a K value
of 70, prepared under the conditions of Example 1, was found
to have a notched impact strength of 19.2 cmkg~cm and an
impact strength at -20 C "without ~reak", according to
DIN 53,453, and a notched ten~ile impact strength of 102 cmkg/cm~
according to DIN 53,448.
E X A M P L E 2: `
In a chl~ination vessel 100 parts b~ weight of low pressure
polyethylene having a reduced specif~c ~iscosity of 1.2 dl/g in
1200 parts by weight of 24 ~ hydrochloric acid to which o.48
part by weight of silicic acid havi~g a ~e~ particle size of
12 ~m and an inner surfacQ v~ 200 cm2/g (~ET) and o.o48 part
by weight of siloxane oil having a visco~ity of 1,000 centi-
stokes at 25 C had been added, were chlcrinated,first at 80 C
29 to a chlorine content of 20 ~ by weightj then the temperature
9 _
:
: :: - , ., : : .: . ~ . :
. .
HOE _73/F 264
S~i8~ '
was rai4ed to 122C and chlorination wa.4 continued until a
chlorine content of 6.6 ~ by weight was reached. The product
had a TAC value of 33 ~ and a MCH value o~ 16 %.
A blend of 10 part3 of the chloropolyethylene obtained
with 90 parts of suspen~qion PVC having a K value of 70, pre-
pared under the conditions specified in E~ample 1, had a
notched impact strength of 38.9 cmkg/cm and an impact strength
at -20 C "without break".
_ X A M P L E 3:
In a chlorination vessel 100 parts by weight of low
pre~sure polyethylene having a reduced specific viocosity of
3.5 dl/g in 1,000 part_ by weight of 20 ~ by weight h-~drochloric
acid were chlorinated first at 70 C to a chlorinQ content of
20 % by weight, then the tempQraturQ was rais~d to 126C and
chlorination was continued to a final chlorine c~ntent of 36.3 %
by weight. ThQ product obtained had a TAC value of 15 ~ and a
MCH value of 21 %.
A blend of tO parts by weight of the chloropolyethylene
with 90 parts by weight of suqpenRlon P~C having a K value of
70, prepared according to claim 1~ had a notched impact strength
of 51.3 cmkg/cm and an impàct strength at -20C "without
break".
-- 10 --
:................... . . . - ~ .... : .